Generalized Dynamic Programming Principle and Sparse Mean-Field Control Problems

In this paper we study optimal control problems in Wasserstein spaces, which are suitable to describe macroscopic dynamics of multi-particle systems. The dynamics is described by a parametrized continuity equation, in which the Eulerian velocity field is affine w.r.t. some variables. Our aim is to minimize a cost functional which includes a control norm, thus enforcing a \emph{control sparsity} constraint. More precisely, we consider a nonlocal restriction on the total amount of control that can be used depending on the overall state of the evolving mass. We treat in details two main cases: an instantaneous constraint on the control applied to the evolving mass and a cumulative constraint, which depends also on the amount of control used in previous times. For both constraints, we prove the existence of optimal trajectories for general cost functions and that the value function is viscosity solution of a suitable Hamilton-Jacobi-Bellmann equation. Finally, we discuss an abstract Dynamic Programming Principle, providing further applications in the Appendix.Comment: This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0

Seasonal Phenology of Reptiles in a Mediterranean Environment (“Castel di Guido” Natural Park, Northern Latium, Italy)

The present work reports the seasonal phenology of the reptiles of the "Castel di Guido" Natural Park near Rome (Northern Latium, Italy). During field observations, between September 2014 and July 2016, transects were carried out along the ecotones of the park, in order to describe the period of seasonal activity of the reptiles present. The area is characterized by Mediterranean mesothermal climate. In the Mediterranean area, reptiles have a broader annual activity range than other European regions, greatly reducing winter latency. Reptile activities start very early, in some case it is possible to observe the snake Hierophis viridiflavus and lizards, such as Podarcis muralis and Podarcis siculus, in thermoregulation activity in the middle of winter. The mild climate that is recorded on average in autumn favors the activity in the period between September and December; Zamenis longissimus is observed regularly in October. Testudo hermanni mates regularly in autumn and it is active until the first decade of December. The research shows that during the winter period reptiles can be observed in activity; for some species, Chalcides chalcides, Podarcis sp., Hierophis viridiflavus, this seems to be a remarkable datum that broad considerably the annual phenology reported in the literature

Desenvolvimento e caracterização de um simulador solar contínuo para módulos fotovoltaicos com traçador de curvas I-V automatizado

Simuladores solares de grande área e exposição contínua são necessários para ensaios light-soaking em módulos fotovoltaicos comerciais. Esta Tese propõe o desenvolvimento, caracterização e testes de um simulador deste tipo com instrumentação e software capaz de monitorar os parâmetros elétricos do módulo em teste durante o próprio ensaio. O simulador foi projetado para atender o procedimento de estabilização previsto na norma IEC 61215 e também possibilitar diferentes ensaios automáticos de exposição solar prolongada. A instrumentação desenvolvida é capaz de obter e tratar as curvas características IV do módulo durante o ensaio em intervalos de tempo desejados, possibilitando traçar perfis de variação das características elétricas dos módulos ensaiados ao longo do tempo. O plano de teste tem dimensões de 1,2 x 2 metros e irradiância de 800 W/m2, que pode ser variada regulando-se a distância entre o plano de medida e as lâmpadas. O simulador foi instalado dentro de um contêiner, sendo composto por 16 lâmpadas de vapor metálico com potência de 1 kW cada. Ventiladores e exaustores são utilizados para o controle de temperatura. A instrumentação é capaz de manter o módulo polarizado no ponto de máxima potência durante o ensaio por meio de fontes de tensão, também utilizadas para traçar as curvas I-V do módulo. A caracterização do simulador é realizada com base nos parâmetros de instabilidade temporal, não-uniformidade espacial e descasamento espectral, demonstrando que o equipamento cumpre com a classificação CCB. Dois módulos com tecnologias de filmes finos foram submetidos a teste de light-soaking. As curvas I-V foram medidas a cada 30 segundos para o módulo CIGS e 20 segundos para o módulo CdTe, com um tempo de aquisição total da curva de 5 s e 200 pares I-V por curva. Os resultados sugerem que a estabilização ocorreu após 5 horas de ensaio para o módulo CIGS e após 50 horas para o módulo CdTe, bem como demonstram a capacidade do simulador em desempenhar as funções para as quais foi projetado, apresentando os perfis de variação dos parâmetros elétricos dos módulos durante o ensaio.Large-area continuous solar simulators are needed for light-soaking tests on commercial photovoltaic modules. The present Thesis proposes the development, characterization and testing of a simulator of this type with instrumentation and software capable of monitoring the electrical parameters of the tested module during the test. The simulator was designed to meet the stabilization procedure provided in the IEC 61215 standard and also enable different automatic light exposure tests. The developed instrumentation is capable of obtaining and processing the I-V characteristics of the module during the test at desired time intervals, making it possible to track change profiles of the electrical characteristics of the tested modules over time. The test plane has dimensions of 1.2 x 2 meters and an irradiance of 800 W/m2, which can be varied by adjusting the distance between the measurement plane and the lamps. The simulator was installed inside a container, consisting of 16 metal halide lamps with 1 kW each. Axial fans and exhaust fans are used for temperature control. The instrumentation keeps the PV module polarized at the maximum power point during the test by electronic loads, also used to trace the module's I-V curves. The characterization of the simulator is performed based on the parameters of temporal instability, spatial non-uniformity and spectral mismatch, demonstrating that the equipment complies with the CCB classification. Two modules with thin-film technologies were light-soaked. I-V curves were measured every 30 seconds for the CIGS module and every 20 seconds for the CdTe module, with a total I-V curve acquisition time of 5 s and 200 data points per curve. The results showed that the CIGS module stabilized after 5 hours of testing and the CdTe module stabilized after 50 hours. They also demonstrate the ability of the simulator to perform the functions for which it was designed by showing the variation profiles of the electrical parameters of the modules during the test

Improved Thermal Transmittance Measurement with HFM Technique on Building Envelopes in the Mediterranean Area

Abstract Although the designed theoretical value of U can be derived from the thermal parameters of layers composing an opaque element, according to ISO 6946:2007, measurements are necessary to confirm the expected behaviour. Currently, the measurements of thermal transmittance based on Heat Flow Meter method (HFM) and according to standard ISO 9869-1:2014 are widely accepted. Anyway, some issues related to difficulties in measurements are present: the roughness of wall surfaces, the proper contact between the heat flow plate and the temperature probes with wall surfaces, undesired changes in weather conditions. This work presents the results obtained in thermal transmittance measurements with a modified HFM method, widely described in this paper. Differences between U-values obtained with the modified HFM method and theoretical ones were in the range 0.6 - 6.5 %. Moreover, the modified HFM method provided a result closer to the theoretical one, when compared to that obtained with standard HFM method (discrepancy with theoretical value were 0.6% and 16.4%, respectively)

First Record of Emys orbicularis (Boulenger, 1882), (Reptilia, Testudinati) in the “Castel di Guido” Natural Park (Northern Latium, Italy): a Case of Interest for Species Conservation

The finding of five specimens of Emys orbicularis (Linnaeus, 1758), (Reptilia, Testudinati) in the “Castel di Guido” Natural Park (Northern Latium, Italy), is reported. This is the first record for the species in the area, regularly monitored since 2006. It is assumed that the species has recently colonized the site through highly populated and degraded territory; the data is of conservation interest, proving the capacity of the species to cross polluted environments

Fast GPU audio identification

Audio identification consist in the ability to pair audio signals of the same perceptual nature. In other words, the aim is to be able to compare an audio signal with a modified versions perceptually equivalent. To accomplish that, an audio fingerprint is extracted from the signals and only the fingerprints are compared to asses the similarity. Some guarantee have to be given about the equivalence between comparing audio fingerprints and perceptually comparing the signals. In designing AFPs, a dense representation is more robust than a sparse one. A dense representation also imply more compute cycles and hence a slower processing speed. To speedup the computing of a very dense audio fingerprint, able to stand stable under noise, re-recording, low-pass filtering, etc., we propose the use of a massive parallel architecture based on the Graphics Processing Unit (GPU) with the CUDA programming kit. We prove experimentally that even with a relatively small GPU and using a single core in the GPU, we are able to obtain a notable speedup per core in a GPU/CPU model. We compared our FFT implementation against state of the art CUFFT obtaining impressive results, hence our FFT implementation can help other areas of application.Presentado en el X Workshop Procesamiento Distribuido y Paralelo (WPDP)Red de Universidades con Carreras en Informática (RedUNCI

Empecé a leer y escribir en el idioma kaingang»: trayectorias de una educación escolar indígena en tierras indígenas del sur de Brasil

El presente artículo expone una serie de narrativas de estudiantes indígenas de las comunidades kaingang ubicadas en el noroeste del estado de Rio Grande do Sul y oeste del estado de Santa Catarina, realizadas en un ambiente universitario, con estudiantes de grado de la Universidade Federal da Fronteira Sul – Campus Chapecó, quienes recuerdan sus experiencias escolares en la educación básica y media en escuelas indígenas y/o en escuelas no indígenas. Se problematiza la escuela, la hegemonía epistemológica eurocéntrica y las posibilidades de que un grupo étnico víctima de epistemicidio y genocidio se apropie de esta institución y, al hacerlo, la transforme en un lugar de «tiempo liberado», de protección y de reafirmación de sí mismos, como un lugar de descolonización. Se busca contribuir a la reflexión sobre el acceso a los procesos educativos formales de los estudiantes indígenas y los significados de la escolarización con miras a preservar sus orígenes, la cultura en la perspectiva de una educación para la pluralidad y para la alteridad guiada por la literatura descolonial y crítica

Averaged time-optimal control problem in the space of positive Borel measures

We introduce a time-optimal control theory in the space \u2133^+ (\u211d^d) of positive and finite Borel measures. We prove some natural results, such as a dynamic programming principle, the existence of optimal trajectories, regularity results and an HJB equation for the value function in this infinite-dimensional setting. The main tool used is the superposition principle (by Ambrosio\u2013Gigli\u2013Savar\ue9) which allows to represent the trajectory in the space of measures as weighted superposition of classical characteristic curves in \u211d^d

Stakeholder perspectives to prevent soil organic matter decline in Northeastern Italy

A transition from conventional to more sustainable soil management measures (SMMs) is required to reverse the current soil organic matter (SOM) losses in the agroecosystems. Despite the innovations and technologies that are available to prevent SOM decline, top–down knowledge transfer schemes that incentivize a certain measure are often ineffective. Here, we discuss relevant outcomes from a participatory approach where researchers, farmers, practitioners and government officials have discussed opportunities and barriers around SMM application to prevent SOM decline. Within a series of workshops, stakeholders identified, scored, and selected SMMs to fieldtests and evaluated the benefits and drawbacks from their application. Results showed that the stakeholders recognized the need for innovations, although they valued the most promising SMM as already available continuous soil cover and conservation agriculture. In contrast, more innovative SMMs, such as biochar use and the variable rate application of organic amendments through precision farming, were the least valued, suggesting that people’s resistance to new technologies is often governed by the socio-cultural perception of them that goes beyond the economic and technological aspects. The valuation of benefits and drawbacks by stakeholders on trialed measures emphasized that stakeholders’ perspective about soil management is a combination of economic, environmental, and socio-cultural aspects, thus corroborating the need for transdisciplinary bottom–up approaches to prevent SOM depletion and increase soil rehabilitation and SOM content